Make #run alias of #start
Split the setup part of the run method - #14 and #12

Now we can do like this:
@num = 1
sc = SpinningCursor.setup do
  banner "My banner"
  type :spinner
  delay 0.5
end

sc.start
@num += 1
sc.stop

Now @num == 2 and the code make it clear that the @num instance variables are the same.
Merge pull request #29 from abinoam/issue14

Fix Issue #14